I don't think, that is considered a bug. Already in FM11 you could assign conditonal format only to fields and text objekts (labels).
Workaround: Create a text object that contains only a space. With the new object attributes round corners you can make it look like a circle. Apply the conditional format to the text object.
Regards, Arnold Kegebein
Thanks for your response Akegebein. Was not saying that inability to assign conditional formating to these objects is a bug. Was saying that in FileMaker 12 contentual menu (right clicking on a pc) it shows that the conditional formating is available (when the square/circle is a button) and shouldn't be. In FileMaker 11 it does not show conditional formating as an option.